Mid-range grades (ABEC 5) are intended for applications such as vehicles, electric motors and industrial machinery. The maximum allowable tolerance on these bearings is 0.0035 mm.

High grade bearings are intended for precision applications like aircraft instruments, jet engines, or surgical equipment. These can often cost many hundreds of dollars each. As a side note, the supplier I use has also sold to NASA. The highest precision bearing they have sold to date was for the international space station and cost $128,000. It was 8 feet in diameter and was an ABEC grade 9.

*(ABEC)-Annular Bearing Engineering Committee. The ABEC scale is the industry accepted standard for the tolerances of ball bearings.